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    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>const命令声明常量值</title>

    <script>
        const PI = 3.1415926;
        console.log(PI);

        PI = 3.14;// Uncaught TypeError: Assignment to constant variable.
    </script>
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<body></body>
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